The present invention relates to mixtures of 1,1,1,3,3-pentafluorobutane (xe2x80x9cHFC-365mfcxe2x80x9d) and water. More particularly, the invention provides compositions of HFC-365mfc and water that are environmentally desirable for use as blowing agents, solvents and aerosol propellants.
Fluorocarbon based fluids have found widespread use in industry in a number of applications, including as refrigerants, aerosol propellants, blowing agents, heat transfer media, and gaseous dielectrics. Because of the suspected environmental problems associated with the use of some of these fluids, especially chlorofluorocarbons (xe2x80x9cCFC""sxe2x80x9d), it is desirable to use fluids of lesser ozone depletion potential such as hydrofluorocarbons, (xe2x80x9cHFC""sxe2x80x9d) and/or hydrochlorofluorocarbons (xe2x80x9cHCFC""s).
Thus, the use of fluids that do not contain CFC""s or contain HCFC""s or HFC""s instead of CFC""s is desirable. Additionally, it is known that the use of single component fluids or azeotropic mixtures, which mixtures do not fractionate on boiling and evaporation, is preferred. However, the identification of new, environmentally safe, azeotropic mixtures is complicated due to the fact that it is difficult to predict azeotrope formation.
The art continually is seeking new fluorocarbon based mixtures that offer alternatives, and are considered environmentally safer substitutes for CFC""s and HCFC""s. Of particular interest are mixtures containing a hydrofluorocarbon and a non-fluorocarbon, both of low ozone depletion potentials. Such mixtures are the subject of this invention.
This invention provides azeotrope-like and compositions of HFC-365mfc and water. The compositions of the invention provide environmentally desirable replacements for currently used CFC""s and HCFC""s since HFC-365mfc and water have zero ozone depletion potentials. Additionally, the compositions of the invention exhibit characteristics that make the compositions better CFC and HCFC substitutes than either HFC-365mfc or water alone.
In one embodiment, the invention provides azeotropic or azeotrope-like compositions comprising effective amounts of HFC-365mfc and water. By xe2x80x9ceffective amountsxe2x80x9d is meant the amount of each component that, on combination with the other component, results in the formation of an azeotropic or azeotrope-like composition. The invention further provides azeotrope-like compositions consisting essentially of from about 50 to about 99 weight percent HFC-365mfc and from about 1 to about 50 weight percent water, which compositions have a boiling point of about 38xc2x0 C.xc2x1about 1xc2x0 C., at about 14.4 psia pressure. The preferred, more preferred, and most preferred compositions of the invention are set forth in Table 1. The numerical ranges in Table 1 are to be understood to be prefaced by the term xe2x80x9caboutxe2x80x9d.
In a particular embodiment, the invention further provides azeotropic compositions consisting essentially of about 98 weight percent 1,1,1,3,3-pentafluorobutane and about 2 weight percent water, which composition have a boiling point of about 38xc2x0 C.xc2x1about 1xc2x0 C. at about 14.4 psia.
In another embodiment, the invention provides blowing agent compositions comprising, consisting essentially of and consisting of the azeotropic or azeotrope-like compositions of the invention.
In yet another embodiment, the invention provides a method for producing polyurethane and polyisocyanurate foams comprising reacting and foaming a mixture of ingredients that react to form the polyurethane and polyisocyanurate foams in the presence of a volatile blowing agent comprising the azeotropic or azeotrope-like compositions of the invention.